Drawing material



Reissued Jan. 23, 1934 Re,

UNITED STATES PATENT OFFICE DRAWING MATERIAL Herman Emanuel Braeg, St. Marys College,

Calif., assignor, by direct and mesne assignments, to St. Marys College, Oakland, Calif., a corporation of California No Drawing. Original No. 1,780,113, dated October 28, 1930, Serial No. 376,293, July 5, 1929. Application for reissue September 26, 1932. Serial No. 634,980

6 Claims. (Cl. 91-68) .This invention re ates to i p ve ts in between the particles to provide gripping surdIaWmg materials. faces for the pastels. For this purpose there It is a p im y object f hi nv nt to pr must be a uniform distribution of the discrete vide on a sheet r board, a su partic l rly particles to a uniform depth over the entire surp -f p n on wi h pas l rs or face. A mere scattering of the materials will Chalks, and Which is susceptible of being u d not do. The layer applied, whether it be silicon repeatedly ut o a on. carbide, garnet, quartz, or any of the non-rust- It s a u t ject of s inv n to p ing ferro-alloys, etc., must be present in at least vid an impr ved radine urfac f r p l a suflicient thickness to prevent the backing 10 boards and the like. member from being seen or felt. 65

I have found that a pastel painting surface The materials may be applied to any suitable may be made up which will readily receive and backing which has been appropriately treated retain the pastel colors and chalks applied thereith an adhesive, such as animal glue, vege. to, and from which these colors may be erased table glue, dextrin, gum tragacanth, gum arabic,

= so that the sheet or board may be used repeatedand other like adhesive substances.

1y. The product of this invention, therefore, is I have found that a surface made up in such of high utility, particularly in respect to the a manner will readily take the friable .colors apeconomy it presents for the beginner or those plied thereto, and if it is desired to reuse the sur- WhO W to p a s face, it is merely necessary to wipe it off with In its broader p e invention fl mprea cloth or eraser, and blow the colors off.

bonds the fixing or emplacement on a suitable Due to the sharpness of the particles formbacking, such as paper, cloth, or cardboard, of ing the improved pastel surface, no matter in an improved receptive surface of a hard subwhat degree of fineness they may be present, stance in finely granulated or powdered form, and also due to the uniform and sufficient spread '2 which is firmly adhered to the backing in a manof the particles, one color may be superimposed ner to be described more in detail hereinafter. on top of previously applied colors, with the Carborundum (silicon carbide) is the preresult that the color last applied shows in its ferred substance for use in the novel combination own particular qualities without blending with here disclosed, but my invention comprehends the others, and this can be repeated quite a the use of any other substance in the form of number of times before the surface becomes fine discrete particles, and having a range of saturated. hardness comparable to silicon carbide, which This susceptibility, greater than heretofore atrange, for the purpose of this disclosure, may be tained, to resume the original surface, or to take conveniently designated as 6 to 9 on the Mohs a separate layer of color on an already existing z'scale of hardness. The materials referred to may one, will be of very great advantage to artists 90 comprehend any of a number of materials, of and students, and is a distinctive feature of which silicon carbide (hardness9), garnet the improved pastel surface of the present in- (hardness6.5-7.5), and quartz (hardness- 1), vention, in contrast to the hitherto known surmay be mentioned as preferred illustrations. faces of sandpaper and the like. The improved 40 These substances are characterized by a keen surface of the present invention will be especially 5 abrasive and gripping quality when presented in appreciated by teachers students, and artists the form of a pastel or chalk receiving surface, who work by the so-called impressionistic and ,and it is precisely in this hardness and keen allied modern methods.

abrasive quality of my improved pastel receiving It will, o C u e, b understood that y Suit- 4 surface that its superior merit consists. able color of background may be used without 9 The materials of the general class described part ng from spirit and scope of y inare obtainable in varying degrees of fineness, and Ve o d the present invention D e my invention comprehends their use in any de the preparation of suitably colored backgrounds gree of fineness desired. For general utility, I by the proper selection of materials having the 50. find that a finely crystalline powder is particurequisite hardness and color, or the materials larly suited for the reception of pastels and used may be dyed v a given C0101 adhered chalks generally. thereto in any suitable manner. Thus, it will The materials to be used must be applied to be seen that the color of the surface which is their backings in sufiicient thickness to insure to be painted may be varied, and the degree of that enough tiny spaces or interstices are formed light or dark to choose for the background in painting a particular subject may be of interest. Commonly, the surface should be as canvases are; i. e., light gray, warm or cold.

Where a gray surface is to be used, the materials may be dyed, as above set forth, or silicon carbide (carborundum), which is black, and quartz, or other like white materials, may be blended in varying proportions to give the desired degree of gray ("value") or of color. It will, of course, be appreciated, that the finer the degree of division of the particles, the more uniform will be the tone of the resulting mixture, which, for the purposes of this invention may be treated and applied as a material of uniform color or value.

While I have described preferred embodiments of my invention, in which an improved surface of a fine-grained, pitted, substantially very hard nature, is provided for the reception ofchalks and pastels, it is to be understood that they are given merely for purposes of illustration, the scope of my invention being defined by the appended claims.

What is claimed is:

1. As an article of manufacture, an improved pastel receiving surface, including a base of fibrous material, and a coating of a monochromatic mix comprising silicon carbide, garnet and quartz powder adhered thereto to a uniform depth.

2. As an improved material for the reception of chalks, pastels, and the like, an intimate, substantially monochromatic mixture of a plurality of varicolored hard crystalline substances such as silicon carbide, garnet and quartz in finely discrete form.

3. As an article of manufacture a pastel picture comprising a pastel receiving surface including a base of fibrous material and a coating of a monochromatic mix comprising silicon carbide, garnet and quartz powder adhered thereto to a uniform depth, and a vari-colored coating of pastel colors applied to such surface.

4. A pastel picture, comprising a backing, a coating of adhesive on the backing, a layer of finely divided abrasive particles applied over the adhesive coating and forming a fine-grained pitted surface having between the abrasive particles tiny interstices which hold the applied pastel colors and permit the superimposition of one color over a previously applied color, and a vari-colored coating of pastel colors applied to and adherent in the pitted abrasive surface.

5. A pastel picture, comprising a backing, a coating of adhesive on the backing, a layer of finely divided hard, sharp abrasive particles applied over .the adhesive coating and forming a monochromatic fine-grained pitted surface having between the abrasive particles tiny interstices which hold the applied pastel colors and permit the superimposition of one color over a previously applied color, the abrasive layer being of sufficient thickness to prevent the backing from 'being seen or felt, and a vari-colored coating of pastel colors applied to and adherent in the pitted abrasive surface.

6. A pastel picture, comprising a backing, a coating of adhesive on the backing, a layer of fine, sharp abrasive particles applied over the adhesive coating and forming a fine-grained pastel receiving surface, and a vari-colored coating of pastel colors applied over such surface.

HERMAN EMANUEL BRAEG. 

